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Topic: Infection (Read 3685 times)

I use a 26 cu foot chest freezer with a Johnson controller for my fermentation chamber. A while back I was making a few batches of various lagers (four in total) and had them fermenting in the chest freezer. I got lazy for a couple of these beers and didn't make yeast starters. As a result the beer, all the beer, got horribly infected, lactobacter most likely. OK flash forward a few months and I placed another couple of beers in the freezer and they also got infected.

I suspected a sanitation issue. I tore down all my equipment and scrubbed, pbw'd, and star sanned everything. I use a blichmann thermonator plate chiller and I pumped pbw at 150 deg thru it for about four hours. Then cooked it at 350 deg in the oven and pumped pbw back thru it. Then I soaked it in star san for an hour.

I made another couple of batches and didn't place them in the freezer. No issues. Then I made a run of the mill ESB, a recipe I have brewed dozens of times with no issues and placed the beer in the freezer and viola infection. The ESB was pitched with dry yeast that was rehydrated exactly as specified by the directions.

Here's the question can a freezer harbor a lactobacter infection and if so how do you get ride of it?

"Lactobacter" is not anything I'm familiar with - perhaps you meant lactobacillus or acetobacter? The first one will produce a clean sourness, sometimes with a white geometric film on the skin of the fermenting beer. The latter will basically produce vinegar.

So if you did, what did you taste?

Have you unplugged, defrosted and completely cleaner your freezer? That seems like a logical place to go from here.

I ferment in a 100-year old basement. Mildew, spiders, and dog hair galore.

Point is - the location of your fermentor is relatively unimportant. The beer should be protected by the fermentor, unless you're constantly opening the lid/stopper OR your fermentor has a leak (bucket/lid seal, carboy stopper, empty airlock).

The most probable is that you're letting bugs in when you sample in the freezer OR your airlock is empty.

The liquid inside the airlock can be sucked inside the fermentor during fermentation, if you burp the lid of a bucket, or if you move the fermentor. Make sure your airlocks are full before and after fermentation and periodically during lagering.

Don't open the lid/stopper all the time! If must sample IN the fridge, wipe down the surrounding area and lid, spray with Star-San, quickly sample and cap, then wipe the Star-San off. Or just pull out the fermentor when sampling.

I will keep an eye on the fluid level in the airlocks. I do not sample in the freezer. On the last beer, the esb, I didn’t even pull a sample at all. Filled the airlock with everclear and left it alone for two weeks and kegged.

I haven’t defrosted the freezer since its set at 65 degree and has no frost build up on it.

This thread jinxed me. Actually it was my own laziness. I spilled a very small amount when I placed my fermentor in the freezer two weeks ago. This morning I discovered it had molded and my beer seemed to have a hot fusel sour smell to it. Looked fine but dumped to be on safe side. I unplugged freezer and sprayed down with bleach water. Left lid open to air dry.

Lesson 1 don't be lazy with spills Lesson 2 wipe down with bleach water every batch.

The beer had a very sour rancid flavor that overwhelms all other flavors. The beer was also cloudy with a fine white haze. My uninfected beer tends to be very clear. Also this flavor increases with time so after about a week and a half the beer is so bad it is impossible to drink more than a couple of sips.

Since I don't have a microscope I am guessing this is acetobacter. Am I incorrect in this guess?

I thought of the bung thung also so I threw them out and ordered new ones.